Discovery of the First α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptor Antagonist Dependent upon Transmembrane AMPA Receptor Regulatory Protein (TARP) γ-8

J Med Chem. 2016 May 26;59(10):4753-68. doi: 10.1021/acs.jmedchem.6b00125. Epub 2016 Apr 29.


Transmembrane AMPA receptor regulatory proteins (TARPs) are a family of scaffolding proteins that regulate AMPA receptor trafficking and function. TARP γ-8 is one member of this family and is highly expressed within the hippocampus relative to the cerebellum. A selective TARP γ-8-dependent AMPA receptor antagonist (TDAA) is an innovative approach to modulate AMPA receptors in specific brain regions to potentially increase the therapeutic index relative to known non-TARP-dependent AMPA antagonists. We describe here, for the first time, the discovery of a noncompetitive AMPA receptor antagonist that is dependent on the presence of TARP γ-8. Three major iteration cycles were employed to improve upon potency, CYP1A2-dependent challenges, and in vivo clearance. An optimized molecule, compound (-)-25 (LY3130481), was fully protective against pentylenetetrazole-induced convulsions in rats without the motor impairment associated with non-TARP-dependent AMPA receptor antagonists. Compound (-)-25 could be utilized to provide proof of concept for antiepileptic efficacy with reduced motor side effects in patients.

MeSH terms

  • Calcium Channels / metabolism*
  • Drug Discovery*
  • High-Throughput Screening Assays
  • Humans
  • Molecular Docking Simulation
  • Molecular Structure
  • Receptors, AMPA / antagonists & inhibitors*
  • Receptors, AMPA / metabolism


  • CACNG8 protein, human
  • Calcium Channels
  • Receptors, AMPA